Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Virology > 10a: vir-cell interaction > Flashcards

10a: vir-cell interaction Flashcards

1
Q

Types of Virus-cell interactions:

A

struggle for life:

  • resistance
  • interferon production
  • latency
  • persistent infection
  • oncogenicity
  • Cytopathic effect (CPE)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is ment by Abortive infection and Productive infection in Virus-cell interactions?

A
  • Abortive infection: no virus release

- Productive infection: virus release and shedding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are Interferon (IFN)?

A

IFN: cell-coded mediator protein - cellular defence mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are Interferon inducer?

A

dsRNA, RI forms –> cascade - IFN release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the IFN effects?

A

occurs: on the neighbouring cell
- structural changes on the cytoplasmic membrane -> decrease in penetration
- L-RNAse: mRNA degradation
- Proteinkinase: protein production inhibited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the different IFN types?

A
  • IFN-alpha (epithel, leucocytes)
  • IFN-beta (fribroblast)
  • IFN-gamma (lymphocyte)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is special about the IFN-alpha and IFN-beta types?

A
  • heat and pH resistance

- viral induction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is special about the IFN-gamma type?

A

antigen, mitogen induces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is the IFN virus/host specific?

A
  • not virus specific

- host specificity (bovIFN, hulFN)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the problems in therapy of IFN?

A
  • expensive
  • parental use, short-term efficacy
  • the inducers (poly-inozine, poly-cytidine) are toxic
  • toxic side effect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Latency

A
  • after infection the virus does not multiplicate -> balance with the cell
  • only the nucleic acid and eary proteins are present
  • no virus shedding, no clinical sign, but carrier!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Types of viruses that show latency:

A
  • Episoma (Papilloma-, Herpesviridae)

- Integration - provirus (Retro-, Polymaviridae)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Persistent infection:

A
  • virus production, but no severe cell damage –> continuous shedding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Types of viruses that shows Persistent infection:

A

Flavi-, Retro-, Paramyxo-, Papillomaviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Oncogenic effect:

A
  • cell proliferation
  • less differentiated cell forms (“ancient”)
  • less effective cell forms
  • usually not able to function effectively –> tumors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Oncogenic DNA-viruses:

A

Papilloma-, Polyoma-, Adeni-, Herpes-, Pox-, Hepadnaviridae

17
Q

Oncogenic RNA-viruses:

A

Retroviridae

18
Q

Types of tumors:

A
  • Benignant

- Malignant

19
Q

What is typical for the Benignant type of tumor?

A

limited, less invasive, less destructive

20
Q

What is typical for the Malignant type of tumor?

A

Invasive, destructive

21
Q

Mechanisms of viral oncogenesis:

A
  • Activation of cellular oncogenesis
  • Expression of viral oncogenesis
  • Viral proteins with consequent oncogenic effect
22
Q

Virus typical for activation of cellular oncogenesis?

A

Retroviridae (Avian leukosis virus, Feline leukosis virus)

23
Q

Activation of cellular oncogenesis?

A
  • DNA integration into the cellular genome
  • Near by c-onc genes
  • Retroviral LTR regions –> intensive promoter - translation.
  • ->c-onc activated - oncoprotein expression - cell proliferation
  • -> slow developing lymphatic tumors (leukemias)
24
Q

viruses typical for expression of viral oncogenesis:

A

Retroviridae (Avian sarcoma virus, Feline sarcoma virus)

25
Q

expression of viral oncogenesis:

A
  • recombination between the cellular and proviral genome
  • transposition of the c-onc gene into the virus genome –> v-onc!
  • the oncogene is carried by the virion
  • after infection quick oncoprotein production
  • fast developing malignant tumors (sarcoma, carcinoma)
  • the v-onc gene is not essential for the virus
  • replacing essential genes (envelope protein gene)
  • defective particles - envelope from leukosis viruses.
26
Q

Viral proteins with consequent concogenic effect:

A
  • oncogenic DNA viruses
  • viral modulator proteins control the cell machinery
  • inativation of cellular anti-oncogenic proteins
  • inhibition of the apoptosis (Adenoviridae)
  • usually benignant tumors
27
Q

What happens in in vitro cell cultures?

A

malignant transformation

- contact inhibition is terminated: microtumors

Virology (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions